Torpedo intermediate section



2 Sheets-Sheet 1 INVENTOR. RAYMOND E. KARP ATTORNEYS.

R. E. KARP TORPEDO INTERMEDIATE SECTION Sept. 26, 1961 Filed May 17, 1960 2 Sheets-Sheet 2 INVENTOR. RAYMOND E. KARP 4. ATTO RYS.

Sept. 26, 1961 R. E. KARP ToRPEDo INTERMEDIATE SECTION Filed May 1'7, 1960 bvb iin"

6 Claims. (Cl. 114-20) (Granted under Title '35, U.S. Code (1952), sec. 266) The invention described herein may be manufactured and used by or for the Government of the United States of AAmerica for governmental purposes without the payment of any royalties thereon or therefor.

This invention relates to torpedoes and more particularly to improvements in their intermediate sections and methods of making same.

It is customary practice in torpedoes to fabricate their hulls in a plurality of tandem sections, removably secured together to permit assembly and maintenance of their internal components. The number of sections may vary but usually consist of a minimum of three sections, such as a nose section containing the warhead, a tail cone section containing the propulsion apparatus and an intermediate section containing a source of power, such as a battery or fuel. This invention relates to that type of torpedo which is propelled by a gas operated engine, such as a turbine, disposed in the tail section which receives hot gases provided by a burning solid propellant fuel contained in a central or intermediate section.

Since present submarine targets are capable of descending to considerable depths in their evasive tactics it has become necessary to design torpedoes which will operate at such depths which has imposed high exhaust back pressures on their engines and consequently high gas inlet pressures. These high pressures have in turn required that torpedo hulls be constructed of relatively thick material, this adding considerable weight which decreases the pay load or warhead capacity ofgexplosive. It therefore becomes apparent that it isdesirable to construct torpedo hulls as light as possible yet to withstand the relatively high pressures, both internal and external, to which they are subjected. For a torpedo adapted to operate at say 1000 feet the external pressure may be of the'order of 400 p.s.i. and the internal pressure produced by its burning propellant may be of the order of 2000 p.s.i. The torpedo which forms the subject of this invention is designed principally for dropping from aircraft which also imposes severe temporary water entry shock forces on its hull and components.

Torpedoes of the type just referred to Vare transported by aircraft, often at extreme altitudes where air temperatures are so low that certain of the torpedo components will not function at all or will not function with optimum results. As will be apparent, the torpedo must therefore be maintained heated in some manner so that at the time of launching it will function properly. It has been proposed, for example, to carry the torpedo in a heated bomb bay of the aircraft. This is not entirely satisfactory since it imposes design restrictions on the aircraft which have been found objectionable. Heated blankets and other devices have also been proposed which are not entirely satisfactory.

One of the principal objects of the invention is to provide a light weight torpedo section, which may be fabricated at relatively low cost and is suiciently strong to withstand the various forces to which it is subjected from the time of launching, through Water entry, and its subsequent descent and operation at considerable water depth.

Another principal object is to provide a torpedo sec- "atent C tion of the foregoing type with self contained means for j v `Patented Sept. 26, 1961 ice maintaining it at optimum operating temperature While being transported by an aircraft.

Another object is to provide such torpedo with readily replaceable solid propellant grains of different sizes for either normal full run operating conditions or for shorter test or exercise runs.

Another object is to provide novel methods of fabricating a torpedo section of the type referred to.

Still further objects, advantages and salient features will become more apparent from the description to follow, the appended claims and the accompanying drawing, in which:

FIG. l is a side elevation of a torpedo employing an intermediate section constructed in accordance with the invention;

FIG., 2 is an enlarged longitudinal central section of the torpedo section; Y

FIG. 3 is an enlarged section taken on line 33, FIG. 2;.

FIG. 4 is` an enlarged section taken on line 4 4, FIG. 2;

FIG. Sis a developed plan of a heater element blanket employed in the fabrication, and v FIG. 6 is an alternative form of propellant container for use with the invention. Y p

Referring to the drawing, and first to FIG. l, the subject of the invention relates to kimprovements in a central or intermediate section 10 disposed between aV warhead 11 and tailcone section V12 oftorpedo 13. A`As best shown in FIG, 2, section 10 comprises, in general a cylindrical hull 14, the forward end or edge V15 and rearward similar Yend :16 of whichare'provided with anyA suitable joint for detachably connecting it to the warhead and tailcone'sections. Since such jointsV are well known in the art, any suitable'one Vof which Vmay be employed, details are omitted in the interests Yof clarity. The forward end of the section'is provided with a compartment which contains a guidance and control package or panel 17, shown in dotted` lines, and substantially` all ofthe remaining rearward portionv contains a solid propellant 18,which upon burning, delivers hot gas under pressure to theV propulsion engine (not (shown) which Yis disposed within tail cone section 12. The tail cone section is also provided with the conventional Vrudders and "elevatorsrand their associated control mechanisms which are controlled by electricalsignals produced by the guidance and control panel', the latter obtaining its intelligence from a suitable Ytransducer disposed, for example, at the extreme for- Yward end of the nose section. Since these devices are all conventional in homing torpedoes, detailed illustration is Ydeemed unnecessary. It becomes apparent, however, at Ythis point of the description, that it is essential to provide electrical communication between guidance mechanism disposed in the tail cone and electrical apparatus disposed forward of the propellant grain which, in view of the consumable characteristics ofthe propellant grain which substantially fills the diameter of the hull, leaves no available spacen for electrical conduits except the annulus Vformed'between the peripheral surface of the grain and the outer. surface of the hull. As will subsequently appear in more detail, portions of this space are utilized for electricalconductors in a novel manner to provide adequate electrical insulation and structural support for the conductors.

The ends of lthe combustion chamber which' contain solid propellant grain 18 are closed by dished or boiler head type bulkheads 19, 20, formed of metal such as steel. Bulkhead 19 is provided with a peripheral flange 21 which is slidably received within one end of a steel tube 22, sealed by an O-ring 23, and restrained against rearward movement by a a snap ring 24 which engages a mating, groove in tube Y22. The concave 'side of .this bulk- Q sa head is iilled with a heat insulating material, such as molded asbestos, secured to it by a metal plate 2S which is secured to the bulkhead by a plurality of suitable screws 26. A nozzle 27 is secured to the bulkhead in any suitable manner, the rear end of which communicates (not shown) with the gas engine disposed in the tail cone section. Forward bulkhead 20 is of similar construction, its concave side being filled with synthetic rubber which forms a shock absorbing pad for grain 18 when the torpedo enters the water after an air drop. The rear face of ther ubber abuts a llame inhibitor 28 which surrounds the peripheral surface of the grain and its forward end, its rear end being uninhibited to permit burning. This bulkhead is also slidably disposed within tube 22, sealed by an Oring 29, and held in place abutting the front end of the grain by an annular nut 30 which threadedly engages 4tube 22. Since the peripheral edges of both of the bulkheads are slidably disposed in tube 22., rather than integrally connected to it as in conventional boiler head construction, it will be apparent that there are no junctures subjected Ito combined stresses which require a thickened and heavier section, the tube being subjected only to tension and the bulkheads to normal boiler head stresses without combined juncture stresses which results -in a lighter weight construction without s-acriiice of strength. A spacer ring 31 abuts the front end of the grain 4and when nut 30 is tightened the grain is held against axial movement between this spacer ring and the shock absorbing pad formed in the front bulkhead. The annular space between the peripheral portion of inhibitor 28 and tube 22 is filled with a high temperature molded insulation material 32, into the bore of which is pressed a molded asbestos liner 33. A tube 34 is secured to bulkhead 19, the rear end of which receives an igniter device 35, which upon electrical actuation, projects ame through the tube igniting the propellant grain.

The forward end of tube 22 terminates in a ange 36, tapering in thickness, which is joined to a spaced aluminum tube 37 by fiberglass material 38. This material also extends rearwardly, covering substantially the full length of tube 2.2 and embedded within this material are electrical conduits 39 and heater element 40, the construction details of which may be better understood by the process of making the hull section.

Steel tube Z2, in its most simple form, is constructed `as an integral forging, or is drawn to approximate shape. Alternatively, the central portion may be rolled to shape and the longitudinal edge welded, the end rings being similarly formed, or formed as integral rings, the rings being circumferentially welded to the central section. In either construction, `all surfaces are then machined to iinished dimensions. Aluminum tube 37 may be similarly rolled and the ends butt welded after which it is machined, or it may be machined from an endless tube. The precise manner in which both of these tubes are formed will depend upon strength requirements and costs of fabrication. In general, the most inexpensive construction is to be chosen consistent with the requirements for strength and minimum weight.

After the tubes have been machined Ithey are supported in axially spaced relationship on a rotatable mandrel which is provided with a cylindrical surface joining the inner surfaces of flange 36 of tube 22 and flange 41 of tube 37. Epoxy resin is applied to the outer surfaces of these ilanges and at least one lapping layer 49 of fiberglass is applied under tension over the mandrel and ilanges `and resin applied to the fiberglass, between layers, which is allowed to set and cure. The heater elements 40, which have previously been bonded between two layers of woven fiberglass, thus forming a sheet blanket 56, are then applied to the outer surface of the previously formed cylinder of iiberglass and their end leads 51 are either extended forwardly through apertures 42 in ring 37 or extended rearwardly along tube 22 and temporarily retained in place. Additional layers 52 of woven fiberglass are similarly wound and bonded over the heater element blanket until a desired wall thickness is obtained. At least one overlapping layer 49A of woven berglass is then applied to tube 22 and the heater leads laid longitudinally along this layer, the ends of the heater leads being carried through apertures 43. A similar heater element blanket *50A is then applied over these exposed leads, this blanket covering tube 22 only. At least one iinal lapping layer 53 of fiberglass is next applied over the entire length of the previously applied fiberglass. Several layers will usually be desired, however, to permit machining the entire outer surface to a smooth round nish. In the nal construction, as illustrated in FIGS. 3 'and 4 the heater elements will be near the inner surface of the section between tlanges 36 and 41 and between layers of the thinner iiberglass surrounding tube 22. Lead wires 39, extending through and between apertures 42, 43 may be yapplied at any time during the winding process, it being desirable to provide a maximum amount of outer overlay of beriglass to ensure maximum insulation from the water which will surround the fiberglass section during operation.

As shown in FIG. 5, the heater element blankets 50 may be preformed, laying the element in a desired pattern on a sheet of iiberglass after which lanother layer of fiberglass is bonded by resin to the rst layer with the heater elements disposed between. This provides `a convenient manner of handling the otherwise delicate heater elements. The heater elements 40 are preferably woven into a woven band of fiberglass extending along the warp threads with crossing wires #also extending along the weft threads. This ensures continuity between ends of the band in event several wires are broken during handling or otherwise. Such material is a commercial product manufactured by Electroiilm, Inc. of North Hollywood, California. Insulation 32 is next molded into place within tube Z2 and preformed asbestos liner 33 axially inserted into the bore of insulation 32.

FIG. 6 illustrates a propellant supply source which Imay be employed with the 'hull section previously described in lieu of the long propellant grain intended for use in war shots. This grain is considerably shorter and is used for exercise runs of the torpedo. Details of the propellant grain, exhaust nozzle, igniter are essentially the same, the principal difference being that a steel cylinder 44 is provided which contains the grain. The rear bulkhead may be formed integral with the cylinder and the forward bulkhead may be slideably inserted into the cylinder as in the construction previously described. AS will be apparent, the hull is not subjected to internal pressure, produced by the Iburning propellant, tube 44, instead, being subjected to such pressure. The entire unit replaces both bulkheads and the grain of the construction shown in FIG. 2 and is secured in place by snap ring 24, annular abutment 45 and a ring 46 which is secured to the rear bulkhead by screws 47.

Obviously many modiiications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that within the scope of the Iappended claims the inventionmay be practiced otherwise than as specifically described.

What .is claimed is:

l. A torpedo intermediate hull section comprising a first 'annular metallic portion adapted to be connected at one end thereof to a rearward hull section, a second annular metallic portion spaced axially from said rst portion adapted to be connected at one end thereof to a forward lhull section, an annular portion of fiberglass material connecting adjacent ends of said portions and bridging the space therebetween and surrounding said rst portion `in engagement therewith, a bulkhead slideably disposed within said first portion adjacent each end thereof, means for sealing the periphery of each bulkhead to said rst portion to prevent gas leakage, a solid propellant grain disposed within said iirst portion and between said bulkheads, and electrical conductors embedded within said fiberglass material extending longitudinally of same adapted to connect electrically operated components disposed within said rearward and forward hull sections.

2. Apparatus in accordance with claim 1, including an electrical heater element embedded wit-hin said berglass material.

3. Apparatus in accordance with claim 1 wherein said bulkheads are provided with outwardly dished central portions, and a shock .absorbing material filling the inner concave side of the forward bulkhead providing an abutment -for the front end of said grain.

4. Apparatus in accordance with claim l including an annular portion of heat insulating material disposed between the inside surface of said rst portion and the ontside surface of said grain.

5. A torpedo intermediate hull section comprising a rst annular metallic portion adapted -to be connected at one end thereof to a rearward hull section, a second annular metallic portion spaced axially from said rst portion adapted to be connected at one endy thereof to a fonward hull section, an annular portion of liberglass material connecting adjacent ends of said portions and bridging the space therebetween and surround-ing said Y cylindrical portion disposed within and spaced from saidl first portion and having an open end, a solid propellant grain disposed Within said cylindrical portion, and a bulkhead member slideably disposed Within oneend of said cylindrical portion and closing said open end, said unit being bodily slideable-into and removable Ifrom said first portions, and means 'for retaining said unit against axial movement when disposed within said irst portion.

No references cited. 

